Fuse-block for electric circuits



(No ModeL) A E. A. SPERRY.

FUSE BLOCK FOR ELECTRIC CIRCUITS.

No. 476,570. Patented June 7.1892,

7422766666. five/Z707."

UNITED STATES PATENT OFFICE.

ELMEE A. sPEERY, or cnIoAso, IILINoIs.

FUSE-BLOCK FOR ELECTRIC CIRCUITS.

SPECIFICATION forming part of Letters Patent No. 476,570, dated June '7,1892.

Application filed March 19, 1891. Serial No. 385,581. (No model.)

To all whom it may concern:

Be it known that I, ELMER A. SPERRY, a citizen of the United States,residing at Ohicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Fuse-Blocks for ElectricGircuits, of which the following is a specification, reference being hadto the accompanying drawings, in which similar letters of referenceindicate like parts in all the figures.

The well-known use of a fuse-wire in electric circuits is to protect theelectrical apparatus from the effects of accidental excess of current orto prevent diversion of the current from its normal path by meeting andopening the circuit.

My invention is of especial advantage when used in electric circuitswhere the excess of current against which it is intended to affordprotection is caused by some momentary accidental disturbinginfluence-as, for instance, in motor-work, where sudden increase in thework may either stop the motor or so reduce its speed as to lower thecounter electro-motive force sufficiently to permit the passage of sucha volume of current as to endanger the conductors, and, for a furtherinstance, in the case of a lightning-arrester, where the dynamo-currentmay follow the static discharge to the ground and become diverted fromits intended course. In such cases it is of advantage to have afuse-wire in the circuit adapted to melt in any excess of current andopen the circuit, and also in such cases it is generally true that themomentary or accidental cause of the excess of current is of frequentoccurrence, where it happens at all, rendering it necessary to insert anew fuse-wire frequently into the circuit to replace one that has beendestroyed in order not to interrupt the progress of the motor-work inthe one instance and in the case of the lightning-arrester to provideimmediately for another discharge. To provide means for doing thisquickly and with entire safety to the operator is the object of myinvention; and I accomplish the object by the use of the device shown inthe drawings, in which Figure 1 is a perspective view of my inrprovedfuse-block. Fig. 2 is aplan view. Fig. 3 is a section of Fig. 1 throughthe dotted line a: 00.

In the figures,A is a base of insulating material, having mountedthereon two standards 0' and O.

B is a block of insulating material provided with metallic end hubs l)and l), which are j ournaled in the standards 0 and O, respectively.Upon the hub 12 and integral therewith are the binding-terminals g g gg, disposed one on each side of the block B and in electriccommunication with the standard 0 through the journal therein. There arealso disposed 011 the block B, one on each side thereof, the fourbinding-terminalsffffi insulated from the plate I) and from each other.

N is a binding-terminal for the line-wire and is formed integral withthe standard C.

J is also a binding-terminal for the line wire and is in electriccontact with the spring S, which is adapted to press against theterminal f on the under side of the block 13.

I construct terminals f with flat surfaces and give them considerablewidth in the direction tangential with the rotation of the block, sothat the pressure of the spring S against the face tends to adjust theblock D to the position of best contact between the spring and theterminal and to retain it there, as shown in Fig. 3.

In connecting my improved fuse-block for use with a lightningarrester Iuse, also, the terminal D and place in the terminals J and D the carbonpoints 0 c. The terminal N is then connected with the ground G and theterminal D with one of the line-wires Z by the wire Y, as is usual andwell known.

If I desire to use my improved fuse-block simply in circuit, I connectthe line-wires to the terminals .I and N.

M M M M are fuse-wires extending between the terminals g on the hub band the separate terminals f.

V is a hand-wheel mounted on the journal of the block B and adapting itto manual rotation.

In the use of my improved fuse-block by the rotation of the block B thefuse-wires M may be brought successively into circuit through thesuccessive contacts of the terminals f with the spring S, the circuitbeing from the terminal J through the brush S, the terminal in contacttherewith, the fuse-wire attached to such terminal to the hub (3, andthence through the standard C to the terminal N. It now the fuse-Wire incircuit should become destroyed through excess of current, a simplequarter-rotation of the fuse-block 13 brings into circuit the succeedingfuse-wire and at the same time throws out of circuit the terminals ofthe destroyed fuse, enabling the attendant to insert a new one in placethereof without danger to himself.

The block B is chamfered slightly at the corners in the path of thebrush S to prevent undue deflection'thereof when the block is rotated.

Vt hat I claim as new, and desire to secure by Letters Patent, is-

1. A revoluble block of insulating material having a hub in contact witha conductor, terminalsf, mounted upon the block and insulated from eachother and adapted bya rotation of the block to be brought successivelyinto contact with the spring in contact with the terminal, as J,fuse-Wires connecting the hub to the terminals f, and a hand-wheel, asW, on the shaft of the block, ada ning it to manual rotation, incombination with a supporting-base.

2. In combination with a base of insulating material, a revoluble fuseblock mounted thereon, flat-faced terminals, as f, mounted on thefuse-block, terminals, as N and D,

mounted on the base, one of which is connected with the ground and theother to the line-Wire, fuse-Wires mounted upon the block connecting theterminals 1" with the terminal N, and a terminal, as J, mounted upon theblock in proximity to the terminal D for static dischar e, and a spring5, attached to the terminal J, adapted to press in succession againstthe terminals j and adjust the position of the block to that of bestcontact between the spring and the terminals f and to maintain it there.

Executed this 12th day of March, 1801.

ELMER A. SPERRY. "Witnesses:

Emma E. JonNsoN, W. R. GOODMAN.

